一个6点图与路的联图的交叉数

On the Crossing Number of Join Product of Path and a Graph of Order Six

一个图G的交叉数cr(G)是把图G画在平面上,在所有画法中所产生的最少的交叉数.由于其结构的特殊性,能够确定两个图的联图交叉数的精确值的图类很少.本文通过圆盘画法这一途径,确定了一个特殊6点图与路P_n的联图的交叉数.

The crossing number cr（G） of a graph G is the minimal number of crossing over all drawings of G in the plane. According to their special structure, the class of Join products of two graphs is one of few graph classes for which some exact values crossing numbers were obtained. Using a new Disk drawing method in this paper we are dealing with the join products of path with graph Q on six vertices, and give the exact values of crossing numbers for the join products Q ＋ Pn, where Pn is the path on n vertices.